CN102681354B

CN102681354B - Decision method and computer

Info

Publication number: CN102681354B
Application number: CN201210061014.5A
Authority: CN
Inventors: 行田裕一; 辻田好一郎
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2011-03-10
Filing date: 2012-03-09
Publication date: 2014-09-10
Anticipated expiration: 2032-03-09
Also published as: KR20120104497A; JP5728259B2; US20120233574A1; KR101390586B1; JP2012191018A; CN102681354A; US8584055B2

Abstract

The present invention relates to a decision method and a computer, and provides a decision method for deciding the exposure condition in an exposure apparatus, comprising a step of selecting an evaluation item of interest from a plurality of evaluation items to be used to evaluate an image formed on an image plane of a projection optical system in correspondence with the exposure condition, a step of selecting, as an auxiliary evaluation item, an evaluation item which is different from the evaluation item of interest and changes a value in the same direction as that of a change in a value of the evaluation item of interest upon changing parameter values included in the exposure condition, and a step of setting an evaluation function including the evaluation item of interest and the auxiliary evaluation item as values.

Description

Determining method and computing machine

Technical field

The present invention relates to for determining determining method and the computing machine of the conditions of exposure of exposure device.

Background technology

In using the step of exposure of exposure device, the photoresist (resist) that the picture characteristics of General Requirements based on hope comes transfer printing to apply to the surface of the substrate such as wafer, and in the situation that the variation of focus and exposure etc. (error) changes picture characteristics hardly.At Japanese Patent Publication No.2008-166777, the people such as T.Matsuyama, " A Study of Source & Mask Optimization for ArF Scanners ", Proc.of SPIE, USA, SPIE, 2009, Vol.7274, p.727408 (document 1), and the people such as Linyong Pang, " Optimization from Design Rules, Source and Mask, to Full Chip with a Single Computational Lithography Framework:Level-Set-Methods-based Inverse Lithography Technology (ILT) ", Proc.of SPIE, USA, SPIE, 2010, Vol.7640, p.764000 in (document 2), the technology of the conditions of exposure in optimization (decision) exposure device has been proposed.Picture characteristics comprises for example size and dimension, contrast, the nargin for exposure (margin) of picture size and the nargin for focus of picture size of image.Conditions of exposure comprises shape (in the upper light intensity distributions forming of the pupil plane (pupil plane) of lamp optical system), numerical aperture (NA) and the aberration of projection optical system of efficient light sources, the pattern (size and dimension) that is arranged in the mask in the object plane of projection optical system and the transmissivity of mask.

When optimization conditions of exposure, about efficient light sources or mask pattern, the target that search subscriber is paid close attention to, for example, for the maximized condition of the depth of focus (DOF) of the live width of specific image.Note, conditions of exposure optimization is not limited to search for increasing the conditions of exposure of DOF.For example, if the aberration of the projection optical system of exposure device always changes, wish that so search suppresses the conditions of exposure of the impact of this aberration variation.For the little exposure device of the fluctuation of exposure, wish that search conditions of exposure is to obtain the nargin of the depth of focus (for the nargin of focus) rather than exposure.If the stage of exposure device (stage) is vibrated widely, wish that so searching image characteristic is for stage vibration immovable conditions of exposure almost.That is, for conditions of exposure optimization, exist and need widely, and various types of conditions of exposures are optimised.

In conditions of exposure optimization, usually, set in advance assessment item (for example, DOF, NILS or live width), and optimization conditions of exposure, makes the value (evaluation amount) of assessment item meet standard.For the evaluation amount large as far as possible assessment item such as DOF or NILS (normalized image logarithm tilts, Normalized Image Log Slope) and so on preferably, optimization conditions of exposure means evaluation amount is maximized.On the other hand, for the evaluation amount as far as possible little assessment item such as linewidth error preferably, optimization conditions of exposure means evaluation amount is minimized.More specifically, by the conditions of exposure given (limiting the parameter of the shape of efficient light sources or the shape of mask pattern) is lower, obtains evaluation amount and change conditions of exposure (repeatedly changing conditions of exposure) according to evaluation amount, carry out conditions of exposure optimization.Conditions of exposure change method depends on mathematical method or algorithm, and various method is suggested.Below, pay close attention to assessment item (evaluation amount) and will be called as optimized cost (cost).Note, optimized cost is called as cost function (merit function) or tolerance (metric) sometimes, or referred to as cost or value.

In the prior art, pay close attention to assessment item and be directly set as optimized cost.For example, in Japanese Patent Publication No.2008-166777, live width (CD) homogeneity (uniformity) etc. is set to optimized cost, and optimum (optimum) efficient light sources shape is obtained.In document 1, co-treatment window or OPE characteristic (live width) are set to optimized cost, and best efficient light sources shape or mask pattern are obtained.In document 2, edge layout (placement) error is set to optimized cost, and conditions of exposure is optimised.

But the present inventor finds, in the prior art, is directly set as optimized cost owing to paying close attention to assessment item, therefore, in some cases, conditions of exposure can not be optimised.

In the prior art, as mentioned above, when changing conditions of exposure, obtain optimized cost value, and the variation based on optimized cost value determines to change the direction of conditions of exposure, makes thus conditions of exposure converge on gradually top condition.Therefore,, when conditions of exposure changes, it is important that optimized cost value changes.

For example, check for making the optimization of the maximized conditions of exposure of DOF.In the prior art, DOF is directly set as optimized cost, and conditions of exposure is changed so that optimized cost maximizes.The value of supposing DOF when conditions of exposure changes becomes large.This is implying and can, by changing conditions of exposure along the reformed direction of conditions of exposure, with high possibility (probability), make the value of DOF larger.As an alternative, the value of supposing DOF when conditions of exposure changes diminishes.This is implying and can, by changing conditions of exposure along the reformed contrary direction of conditions of exposure, with high possibility, make the value of DOF larger.

If even the value of DOF does not change yet when conditions of exposure changes, can not know that so conditions of exposure should reformed direction.More specifically, even when efficient light sources shape or mask pattern change, also almost cannot obtain in some cases the value (that is, DOF gets 0 value continuously) of DOF.When optimized cost is got particular value continuously, can not know that conditions of exposure will reformed direction.Thus, conditions of exposure can not be optimised.

For fear of this problem, the scope that can make conditions of exposure change (search) narrows down.But in this case, conditions of exposure is can be in very narrow scope searched and be optimised in limited narrow scope.This is unpractical, because conditions of exposure can not be optimised in the overall situation.As mentioned above, conditions of exposure can not be optimised sometimes.But prior art had not both been mentioned this problem, certainly do not mention its solution yet.

Summary of the invention

The invention provides favourable technology aspect the conditions of exposure in determining exposure device.

According to a first aspect of the invention, a kind of determining method that determines the conditions of exposure in exposure device is provided, this exposure device comprise for the illumination optical system of mask illumination is unified for by the image projection of the pattern of mask to the projection optical system on substrate, the method comprises: first step, from a plurality of assessment items, select the concern assessment item as the assessment item that will be concerned, described a plurality of assessment item will be used to by comparing and evaluate the image forming accordingly with conditions of exposure in the image planes of projection optical system with the target pattern that will form on substrate, second step, selects the assessment item of the direction change value identical from pay close attention to assessment item directions different and that change along the value with paying close attention to assessment item when change is contained in the parameter value conditions of exposure as auxiliary evaluation project from described a plurality of assessment items, third step, sets to comprise and pays close attention to assessment item and auxiliary evaluation project as the evaluation function of value, the 4th step, changes described parameter value so that the value of described evaluation function more approaches desired value, and for each in a plurality of images that form in the image planes of projection optical system accordingly with described parameter value, calculates the value of described evaluation function, and the 5th step, determine among a plurality of values of the evaluation function that calculates that the parameter value corresponding with the value of evaluation function that meets desired value is as the parameter value being contained in conditions of exposure in the 4th step.

According to a second aspect of the invention, a kind of determining method that determines the conditions of exposure in exposure device is provided, this exposure device comprise for the illumination optical system of mask illumination is unified for by the image projection of the pattern of mask to the projection optical system on substrate, the method comprises: when change is contained in the parameter value in conditions of exposure, calculating to be used to by with the target pattern that will form on substrate compare the assessment item of evaluating the image forming in the image planes of projection optical system value and determine that the parameter value corresponding with the value of assessment item that meets desired value is as the step that is contained in the parameter value in conditions of exposure, wherein, assessment item comprises concern assessment item and the auxiliary evaluation project as the assessment item that will be concerned, described auxiliary evaluation project from pay close attention to assessment item different and in the immovable situation of the value of paying close attention to assessment item when parameter value is changed change value.

According to a third aspect of the invention we, a kind of determining method that determines the conditions of exposure in exposure device is provided, this exposure device comprise for the illumination optical system of mask illumination is unified for by the image projection of the pattern of mask to the projection optical system on substrate, the method comprises: when change is contained in the parameter value in conditions of exposure, calculating to be used to by with the target pattern that will form on substrate compare the assessment item of evaluating the image forming in the image planes of projection optical system value and determine that the parameter value corresponding with the value of assessment item that meets desired value is as the step that is contained in the parameter value in conditions of exposure, wherein, assessment item comprises concern assessment item and the auxiliary evaluation project as the assessment item that will be concerned, described auxiliary evaluation project is got exceptional value when paying close attention to assessment item image abnormity different and that form in the image planes in projection optical system.

According to a forth aspect of the invention, provide the computing machine of carrying out above-mentioned determining method.

The following description of reading exemplary embodiment with reference to accompanying drawing, it is clear that further feature of the present invention will become.

Accompanying drawing explanation

Fig. 1 is for explaining the process flow diagram of determining method according to an aspect of the present invention.

Fig. 2 means the diagram of example of the parameter of the mask pattern shape of setting in the step S102 that is limited to Fig. 1.

Fig. 3 means the diagram of example of the parameter of the efficient light sources shape of setting in the step S102 that is limited to Fig. 1.

Fig. 4 means the diagram of the example of mask pattern.

Fig. 5 means mask pattern and the diagram of the example of the optical imagery that forms in the image planes of projection optical system.

Fig. 6 means the diagram of the example of efficient light sources (shape).

Fig. 7 means the diagram of the example of the optical imagery forming in the image planes of projection optical system.

Fig. 8 means the diagram that defocuses dependence (defocus dependence) of the optical imagery forming in the image planes of projection optical system.

Fig. 9 A and Fig. 9 B mean according to the diagram of the change of the optimized cost value in the conditions of exposure optimization of embodiment.

Figure 10 means according to the diagram of the change of the optimized cost value in the conditions of exposure optimization of prior art.

Figure 11 means wherein can obtain for each conditions of exposure the very narrow diagram of scope of the value of common live width DOF.

Figure 12 means the diagram for the value of the linewidth error RMS in the optimum focusing of each conditions of exposure.

Figure 13 means the dependent diagram that defocuses of the optical imagery that forms in the image planes of projection optical system.

Figure 14 means according to the diagram of the change of the optimized cost value in the conditions of exposure optimization of embodiment and prior art.

Figure 15 means the diagram of the example of the parameter that limits mask pattern shape.

Figure 16 means the diagram of the example of the parameter that limits effective light source form.

Figure 17 means the diagram of the example of the optical imagery forming in the image planes of projection optical system.

Figure 18 means the diagram of the example of mask pattern.

Figure 19 means the diagram of the example of efficient light sources (shape).

Figure 20 means the diagram of the optical imagery forming in the image planes of projection optical system accordingly with the conditions of exposure being optimised in the prior art.

Embodiment

Hereinafter with reference to accompanying drawing, the preferred embodiments of the present invention are described.Note, in all accompanying drawings, identical Reference numeral represents identical parts, and, will not provide being repeated in this description of they.

The present invention is suitable for determining will being used to comprise semi-conductor chip such as IC or LSI, such as the display device of liquid crystal panel, such as the detection means of magnetic head and such as the conditions of exposure in the microcosmic machinery (micromechanics) of various device of the imageing sensor of CCD or the exposure device manufactured.Microcosmic machinery represents to produce technology or this mechanical system self based on micron (micron-basis) mechanical system with advanced function by SIC (semiconductor integrated circuit) manufacturing technology being applied to the manufacture of micromechanism.

< the first embodiment >

Fig. 1 is for explaining the process flow diagram of determining method according to an aspect of the present invention.According to the determining method of the present embodiment, by the signal conditioning package such as computing machine, carried out, and determine the conditions of exposure in (optimization) exposure device, described exposure device comprises for the illumination optical system of mask (groove (reticle)) illumination is unified for the pattern of mask is projected to the projection optical system on substrate.Conditions of exposure is the condition that can set in exposure device.In the present embodiment, conditions of exposure comprises the shape of pattern (mask pattern) of mask and at least one in the light intensity distributions (efficient light sources shape) that will form on the pupil plane of lamp optical system.

In step S102, set and be contained in the parameter in conditions of exposure.In the present embodiment, set the parameter of the conditions of exposure that will be optimised limit efficient light sources shape for example or mask pattern shape.But the parameter being contained in conditions of exposure need be only the physical quantity being associated with conditions of exposure.For example, the NA of projection optical system or can be set to parameter from the amount deriving as extent of projection optical system.

In the present embodiment, about mask pattern, as shown in Figure 2, set the parameter P for the shape of SRAM memory cell (cell) limiting pattern (mask pattern) _a, P _b, P _cand P _d.Pattern shown in Fig. 2 is formed by two rectangles, and, parameter P _a, P _b, P _cand P _dthe length that represents the limit of two rectangles.Note, when calculating the image (optical imagery) of the mask pattern forming on will the image planes in projection optical system, the pattern shown in Fig. 2 is arranged by periodically ad infinitum (infinitely) and is used as mask pattern.More specifically, set the basic pattern group that comprises two patterns shown in Fig. 2, wherein, pattern divides out with 130nm and divides out with 250nm along Y direction along X-direction.As shown in Figure 4, basic pattern group is arranged with cycle of 260nm along X-direction and the cycle with 500nm is arranged along Y direction, forms thus mask pattern.

In the present embodiment, the length that is contained in the limit of the rectangle in mask pattern is set to parameter.Alternately, the coordinate being associated with limit such as the position on summit on each limit or the coordinate of the position of mid point can be set to the parameter that limits mask pattern shape.The transmissivity of mask or phase place also can be set to parameter.

About efficient light sources, as shown in Figure 3, set the parameter Ψ of the shape that limits asymmetric four utmost points (quadrupole) illumination ₁, Ψ ₂, σ _aand σ _b.Parameter Ψ ₁expression is along the angle of the luminous component of the vertical direction location of asymmetric quadrupole illuminating, parameter Ψ ₂expression is along the angle of the luminous component of the horizontal direction location of asymmetric quadrupole illuminating.In addition, parameter σ _arepresent outer σ value, parameter σ _bσ value in representing.Note, as parameter Ψ ₁value equal parameter Ψ ₂value time, vertically the angle of luminous component of location equals the angle of the luminous component of along continuous straight runs location.Thus, the asymmetric quadrupole illuminating of the present embodiment comprises symmetrical quadrupole illuminating (in this case, referred to as quadrupole illuminating).Asymmetric quadrupole illuminating is called as I-Quad illumination sometimes.

In the present embodiment, for asymmetric quadrupole illuminating setup parameter.Alternately, can or there is the illumination setup parameter (for example, outer σ value and interior σ value) of other shapes for ring illumination (annular illumination).

As mentioned above, in the present embodiment, in step S102, set 8 parameter P that limit mask pattern shape and efficient light sources shape _a, P _b, P _c, P _d, Ψ ₁, Ψ ₂, σ _aand σ _b.Note, in the present embodiment, about other conditions of exposure, it is 0.93 that the NA of projection optical system is set (fixing), exposure light wavelength is set (fixing) for 193nm, and exposure polarisation of light (polarization) state is set (fixing) for tangential (tangential) polarization.

In step S104, from being used to evaluate by comparing with the target pattern that will form at substrate a plurality of assessment items of the optical imagery forming in the image planes of projection optical system accordingly with conditions of exposure, select the concern assessment item (concern cost) as the assessment item that will be concerned.

The concern cost of setting in the present embodiment will be described in detail in.Fig. 5 means the diagram of the example of the optical imagery forming in the image planes in projection optical system when the efficient light sources shown in Fig. 3 (asymmetric quadrupole illuminating) throws light on to the mask pattern shown in Fig. 4.With reference to Fig. 5, MP represents mask pattern, and OI represents optical imagery.In optical imagery OI, the desired value of live width LW1 and LW2 and be set as respectively 90nm, 65nm and 100nm along the interval Gap of Y direction (vertical direction).In the present embodiment, wherein for each in live width LW1 and LW2 and interval Gap, with respect to the side-play amount of desired value be 10% or less focus will be called as common live width DOF.Select common live width DOF as paying close attention to cost.The value of common live width DOF is larger, and, for the skew of the focus of projection optical system, the live width of formed optical imagery is more not variation.As mentioned above, because the value of common live width DOF is preferably large as far as possible, therefore, after the optimization of the optimized cost that will describe mean the maximization of optimized cost.

The optical imagery of the present embodiment can be for by calculate arriving the image that the light intensity of each position of the image planes of projection optical system obtains (be called simple (simple) optical imagery, aviation (aerial) image, or referred to as optical imagery) or another optical imagery simply.For example, in order to obtain the image corresponding with resist image, convolution in optical imagery (convolve) represents the Gaussian function of the sour diffusion of resist, or, in some cases, consider the resist model of being expressed by specific equation.This optical imagery is also contained in the optical imagery of the present embodiment.Can by use such as commercially available optical analogy device (simulator) calculate the optical imagery of considering resist model.

In the present embodiment, select common live width DOF (that is, the depth of focus in the image planes of projection optical system) as paying close attention to cost.But, pay close attention to cost and be not limited to this.The assessment item that changes its value according to the variation of conditions of exposure is also fine.For example, as paying close attention to cost, the nargin of can selecting to expose, NILS or for the sensitivity of live width that means the MSD (mobile standard deviation (Moving Standard Deviation)) of the mask stage of exposure device or the vibration of wafer stage.

In step S106, select supplementary costs (auxiliary evaluation project).Pay close attention to different as follows between cost and supplementary costs.Paying close attention to cost is the assessment item self that is concerned (that is, be optimised).Supplementary costs is to be used to the suitably auxiliary evaluation project of optimization concern cost.More specifically, supplementary costs is the assessment item different from paying close attention to cost, and the identical direction of the direction changing along the value with paying close attention to cost when conditions of exposure changes changes its value.In the present embodiment, as supplementary costs, select linewidth error RMS in optimum focusing (that is, the difference between the size of target pattern (desired value) and the size of the mask pattern image that forms) in the image planes of projection optical system.

In step S108, by paying close attention to cost and supplementary costs is combined, set as comprising and pay close attention to cost and supplementary costs as the optimized cost (evaluation function) of the function of value.In the present embodiment, by following mode, set optimized cost.

Pay close attention to cost: common live width DOF (nm)

Supplementary costs: the linewidth error RMS (nm) in optimum focusing

Optimized cost: pay close attention to cost-supplementary costs

If conditions of exposure is improper, be selected as so desirable 0 value of common live width DOF of paying close attention to cost.On the other hand, linewidth error RMS independently gets the assessment item of particular value (for example, 0) continuously with conditions of exposure.Linewidth error RMS is the assessment item of (than common live width DOF more sensitively) change value according to the change of conditions of exposure and continuously and sensitively.Thus, the optimized cost common live width DOF as concern cost being changed sensitively with setting its value according to the change of conditions of exposure as the combined permission of linewidth error RMS of supplementary costs.

In addition, as supplementary costs, need to select such assessment item: this assessment item, for having obtained the conditions of exposure of paying close attention to the value of cost, is got than the little value (absolute value) of value (absolute value) of paying close attention to cost.For example, if supplementary costs is large with respect to the weight of optimized cost, conditions of exposure is in the situation that main what consider is not to pay close attention to cost but supplementary costs is optimised so.In the present embodiment, for can enough its suitably obtaining the conditions of exposure of DOF, the value of linewidth error RMS that is selected as supplementary costs is more much smaller than the value of common live width DOF that is selected as concern cost.Thus, even when by will pay close attention to that cost and supplementary costs are combined sets optimized cost time, in fact can be in the situation that only consider to be selected as the common live width DOF optimization conditions of exposure of paying close attention to cost.Note, if the value of supplementary costs is not less than the value of paying close attention to cost, the unit of capable of regulating supplementary costs so, or, the value of supplementary costs can be multiplied by coefficient, to reduce supplementary costs with respect to the weight of optimized cost.

The value of linewidth error RMS in optimum focusing is less, and to become large possibility larger for common live width DOF.Therefore, be appreciated that as mentioned above, the assessment item that changes its value as the identical direction of direction of independently selecting substituting of supplementary costs with paying close attention to cost, be preferably chosen in to change along the value with paying close attention to cost while changing conditions of exposure is as supplementary costs.

The symbol of supplementary costs when cost and supplementary costs are paid close attention in combination will be explained.When cost and supplementary costs are paid close attention in combination, the value that need to make to pay close attention to cost approaches the direction that the direction of desired value and the value of supplementary costs approach desired value and mates.For example, common live width DOF preferably have large as far as possible value (on the occasion of).On the other hand, linewidth error RMS preferably has as far as possible little value.Thus, in order as in the present embodiment, optimized cost being maximized, need to give negative sign to the linewidth error RMS as supplementary costs and make it and be used as the common live width DOF combination of paying close attention to cost.

In step S110, the parameter value of setting in step S102 changes so that optimized cost value more approaches desired value.For each in a plurality of optical imagerys that form accordingly with parameter value, calculate optimized cost value in the image planes of projection optical system.Note, the parameter value being contained in conditions of exposure changes according to specific mathematical method or algorithm.In the present embodiment, by using Descended simplex method (downhill simplex method) to change parameter value.But, can use any other method such as simulated annealing method or Monte Carlo (Monte Carlo) method to change parameter value.

Note, in Descended simplex method, when the change counting of parameter value little (that is, in the early stage stage), by random number, change parameter value, and, for the optical imagery corresponding with parameter value, calculate optimized cost value.Using after random number changes predetermined number of times by parameter value the change (making optimized cost value more approach desired value) of repetition parameter value in the situation that considering each optimized cost value.While changing parameter value when considering by this way optimized cost value, parameter value changes scope and little by little narrows down, final, parameter value convergence (conditions of exposure is determined (being optimised)).

In step S112, determine whether parameter value has changed the number of times (in the present embodiment, being 350 times) limiting (that is, whether optimized cost value has been calculated the number of times limiting).Note, parameter value wants the number of times of reformed restriction to be set in advance (for example, when setup parameter (S102)).If parameter value has changed the number of times limiting, process and advance to step S114 so.If parameter value does not also change the number of times limiting, process so and advance to step S110 to continue to calculate optimized cost value.

As mentioned above, in step S110 and S112, the parameter value that limits conditions of exposure changes the number of times limiting, and, for each in a plurality of images that form accordingly with parameter value, calculate optimized cost value in the image planes of projection optical system.

In step S114, determining whether a plurality of optimized cost values of calculating in step S110 comprise meets desired value (in the present embodiment, be 400 or larger) optimized cost value (that is, whether having at least one the optimized cost value that meets desired value).Note, the desired value of optimized cost is set (for example,, when setting optimized cost (S108)) in advance.If there is no meet the optimized cost value of desired value, process and advance to step S116 so.If there is the optimized cost value that meets desired value, process and advance to step S118 so.

In step S116, determine whether to change supplementary costs.Note, can be set by the user or automatically set the criterion of step S116.In order to change supplementary costs, process to turn back to step S106, using and select the assessment item different from the current assessment item that is selected as supplementary costs as new supplementary costs.Then in the mode identical with above-described mode, perform step S108, S110, S112 and S114.If supplementary costs should not be changed, process so and turn back to step S110, parameter value is changed to the number of times limiting, and for each in a plurality of images that form accordingly with parameter value, calculate optimized cost value in the image planes of projection optical system.

In the processing of describing in the above, not only consider to pay close attention to cost but also consider to pay close attention to by combination the optimized cost that cost and supplementary costs obtain, carry out optimization conditions of exposure (in comprise parameter value).In step S118, determine whether to remove supplementary costs, that is, set only as the new optimized cost of paying close attention to the function of cost.Note, can be set by the user or automatically set the criterion of step S118.But removing supplementary costs is only the example that new optimized cost is set.By for example reducing the impact of the supplementary costs in the optimization of optimized cost, set new optimized cost.

If do not set new optimized cost, process and advance to step S120 so, using and determine that the parameter value corresponding with the optimized cost value that meets desired value is as the parameter value of setting in step S102.

In order to set new optimized cost, process to advance to step S122, using and only set the new optimized cost (that is, setting concern cost self as optimized cost) as the function of the concern cost of selecting in step S104.Note, after step S114, optimized cost value has been left it and has been got continuously the state of particular value.Therefore,, even when concern cost (in the present embodiment, being common live width DOF) self is set to new optimized cost, as described above, new optimized cost value is also got particular value never continuously

When having set new optimized cost, process and turn back to step S110, to calculate as described above new optimized cost value.Now, the parameter value being contained in conditions of exposure changes the number of times limiting from parameter value corresponding to the optimized cost value with meeting desired value (that is the parameter value, determining in step S120).In step S120, again (newly) determine with in step S110, calculate from parameter value corresponding to the optimized cost value that meets desired value of new optimized cost value, as the parameter value of setting in step S102.Thus, only set and make it possible to optimization conditions of exposure in the situation that only considering to pay close attention to cost as the new optimized cost of paying close attention to the function of cost.

The conditions of exposure that is optimised in the present embodiment (decision) will be described in detail below.Mask pattern MP shown in Fig. 5 is the mask pattern being optimised in the present embodiment.Fig. 6 represents the efficient light sources (shape) being optimised in the present embodiment.The mask pattern shape that table 1 expression restriction is optimised in the present embodiment and 8 parameter P of efficient light sources shape _a, P _b, P _c, P _d, Ψ ₁, Ψ ₂, σ _aand σ _bvalue.In table 1, parameter P _a, P _b, P _cand P _dbe expressed as " A ", " B ", " C " and " D ".Fig. 7 means the diagram of the example of the optical imagery forming in the image planes in projection optical system when the efficient light sources shown in Fig. 6 throws light on to the mask pattern MP shown in Fig. 5.

(table 1)

A	122.74	nm
			B	97.45	nm
C	414.11	nm
			D	55.05	nm
σ _a	0.860
			σ _b	0.682
Ψ ₁	32.43	Degree
			Ψ ₂	56.27	Degree

Table 8 represents the dependence that defocuses of the live width LW1 of the optical imagery that forms in the image planes of projection optical system accordingly with these conditions of exposures and LW2 and interval Gap.In Fig. 8, transverse axis adopts values of defocus (mm), and the longitudinal axis adopts live width LW1 and LW2 and interval Gap with respect to the relative error (%) of their desired value.With reference to Fig. 8, represent that wherein the relative error of live width LW1 and LW2 and interval Gap is ± 10% or the common live width DOF proof of less de-focus region there is the very large value of 566.8nm.

Fig. 9 A means according to the diagram of the variation of the optimized cost value in the conditions of exposure optimization of the present embodiment.Fig. 9 B is the enlarged drawing of the region alpha in the region alpha shown in Fig. 9 A, β and γ.In Fig. 9 A and Fig. 9 B, transverse axis adopts the change counting of conditions of exposure (in comprise parameter), and the longitudinal axis adopts optimized cost value.

With reference to Fig. 9 A, in region alpha (conditions of exposure changes the stage that counting is little), in many cases, can not obtained (that is, becoming 0) as the value of paying close attention to the common live width DOF of cost.Therefore, optimized cost value is dominated by supplementary costs value.From Fig. 9 B, can clearly be seen that, in region alpha, along with changing counting, increase, it is large that optimized cost value becomes gradually.This means that the direction that conditions of exposure reduces along the value that is used as the linewidth error RMS of supplementary costs changes.

When the value of linewidth error RMS diminishes, the value of common live width DOF obtained (getting the value beyond 0).This be due to, for the change of conditions of exposure, the value of the direction that the value of linewidth error RMS diminishes and common live width DOF becomes large direction and has identical trend.

Region beta represents to obtain the stage of common live width DOF.With reference to Fig. 9 A, at conditions of exposure, change counting and surpass 50 stage place, the situation that obtains the value of common live width DOF is almost 1/2.But, when conditions of exposure change counting surpasses 100, almost obtain in all cases the value of common live width DOF.Because the value of linewidth error RMS is more much smaller than the value of common live width DOF as described above, therefore, in this stage, to locate, optimized cost value is by the value leading (that is, can be regarded as the value of common live width DOF) as paying close attention to the common live width DOF of cost.In region beta, conditions of exposure changes, and the value of common live width DOF is increased gradually.

Region γ represents that conditions of exposure changes the stage that counting further increases.In the γ of region, the change amount of optimized cost value reduces.When conditions of exposure change counting surpasses 300, optimized cost value changes hardly.The parameter value being contained in conditions of exposure restrains to determine conditions of exposure.

As mentioned above, in the present embodiment, even when paying close attention to the value of cost can not obtained (that is, the direction that changes conditions of exposure is unknown) time, due to the value chop and change of supplementary costs, therefore, can determine to change the direction of conditions of exposure.When having determined to change the direction of conditions of exposure, As time goes on obtain the value of paying close attention to cost.Finally, pay close attention to the leading optimized cost value of cost, and conditions of exposure is optimised (being contained in the parameter value convergence in conditions of exposure).

To the conditions of exposure optimization (that is, not considering supplementary costs) of prior art be described as a comparative example.In the prior art, pay close attention to assessment item (concern cost) and be directly set as optimized cost.Therefore, common live width DOF is directly set as optimized cost.Figure 10 means according to the diagram of the variation of the optimized cost value in the conditions of exposure optimization of prior art.According in the conditions of exposure optimization of prior art, also use Descended simplex method to change and be contained in the parameter value in conditions of exposure, as in the present embodiment.

With reference to Figure 10, even when the change counting of conditions of exposure (being contained in parameter value wherein) increases, the value of optimized cost (common live width DOF) is also 0.In the prior art, the value of common live width DOF is directly set as optimized cost value, even after conditions of exposure is changed, the value of common live width DOF is also got 0 value continuously.

At conditions of exposure, change the stage place that counting is little, as mentioned above, use random number to set conditions of exposure, and, optimized cost value (feature of Descended simplex method) calculated.In some cases, by the method, obtain common live width DOF (obtaining the value beyond 0).But, if optimized cost value is 0 continuously when changing conditions of exposure, can not know so the direction that changes conditions of exposure.Here, even if be not, do not get the optimized cost value of 0 value but the optimized cost value of also getting same value (that is, remaining unchanged) after conditions of exposure changes is problematic (problematic).In Descended simplex method, the change of conditions of exposure (in comprise parameter value) based on optimized cost value and changing.For this reason, if optimized cost value does not change, determine that so the direction of change conditions of exposure is impossible.In the conditions of exposure optimization of the prior art shown in Figure 10, solution restrains in the region that can not obtain as the value of the common live width DOF of optimized cost value, and conditions of exposure can not be optimised.

By the solution convergence of describing in the region of the value can not obtain in the prior art common live width DOF.Figure 11 means and can obtain for each conditions of exposure the very narrow diagram of scope of the value of common live width DOF.In Figure 11, transverse axis adopts σ than (interior σ value σ _bwith outer σ value σ _abetween ratio), the longitudinal axis adopts outer σ value σ _a, and, the value of drawing the common live width DOF corresponding with each condition.Note, the parameter being contained in remaining conditions of exposure (limits the parameter P of mask pattern shape _a, P _b, P _cand P _dwith the parameter Ψ that limits efficient light sources ₁and Ψ ₂) there is the value shown in table 1 (optimal value).

With reference to Figure 11, the value of common live width DOF is 0 in most region.Obviously, although only have two parameter σ _aand σ _bchange (remaining parameter has optimal value), still, the region of value that can obtain common live width DOF is very little.In fact, owing to there are many parameters that will be optimised, therefore, the quantity of the combination of parameter value is very large, and optimization space is larger than the optimization space shown in Figure 11.In this large optimization space, the quantity of combination of parameter value of value (0 beyond value) that obtains common live width DOF is considerably less, and common live width DOF usually gets 0 value continuously.

Description is selected as to the linewidth error RMS in the optimum focusing of supplementary costs.Figure 12 means the diagram for the value of the linewidth error RMS of each conditions of exposure.In Figure 12, transverse axis adopts σ than (interior σ value σ _bwith outer σ value σ _abetween ratio), the longitudinal axis adopts outer σ value σ _a, and, the value of drawing the linewidth error RMS (nm) in the optimum focusing corresponding with each condition.From relatively can clearly be seen that between Figure 11 and Figure 12, the value of common live width DOF approaches the direction (that is, increasing the condition of this value) of desired value and the value of linewidth error RMS, and to approach the direction (that is, reducing the condition of this value) of desired value identical.

As mentioned above, the value of paying close attention to cost approach desired value direction need to approach the direction of desired value identical with the value of supplementary costs.In the present embodiment, as shown in Figure 11 and Figure 12, the direction that the value that the value of common live width DOF approaches the direction of desired value and the linewidth error RMS in optimum focusing approaches desired value is usually identical, and the combination of paying close attention to cost and supplementary costs is suitable.More specifically, as shown in Figure 11 and Figure 12, when outer σ value changes in specific scope with σ ratio, the change amount (that is, difference) of common live width DOF and linewidth error RMS has identical trend.Note, even for the parameter beyond outer σ and σ ratio, common live width DOF and linewidth error RMS also have identical relation about variable quantity.

When paying close attention to cost and select supplementary costs, for example, as mentioned above, relatively by changes, be contained in the symbol of the difference that the parameter value in conditions of exposure obtains, stipulate to be set to thus the assessment item of supplementary costs.Note, can between step S104 and step S106, provide regulation will be set to the step of the assessment item of supplementary costs.In addition, can produce in advance represent the corresponding relation between a plurality of assessment items table (supplementary costs about pay close attention to cost preferred compositions (in the present embodiment, for the linewidth error RMS in the optimum focusing for common live width DOF)), and can be by show to select supplementary costs with reference to this.If user knows that the assessment item that will be selected (that is, preferred) is as supplementary costs in advance for the assessment item that is selected as concern cost, user can indicate and select this assessment item as supplementary costs so.Note, for paying close attention to cost, select supplementary costs to be not limited to above-mentioned these.Need to only select to change along the identical direction of direction of the value change with concern cost the assessment item of its value.

As mentioned above, in the present embodiment, as direct setting, pay close attention to substituting of assessment item, the function of paying close attention to cost and supplementary costs is set to optimized cost.Even no matter how conditions of exposure changes the value of concern cost but remain unchanged, the value of supplementary costs also changes.Therefore, can know and change the direction of conditions of exposure and make conditions of exposure optimization.

< the second embodiment >

In a second embodiment, will explain following situation: in step S104, select for the live width LW1 of the optical imagery OI shown in Fig. 5 and the common exposure nargin DOF of LW2 and interval Gap as paying close attention to cost.The live width that exposure nargin represents optical imagery is ± 10% or less exposure range at certain focus place with the relative error between its desired value.For all live width LW1 and LW2 and the common exposure nargin of interval Gap, be defined as jointly exposing nargin.In the present embodiment, jointly the expose focus of nargin of 10% or the larger acquisition that can be used as exposure will be called as common exposure nargin DOF.The value of common exposure nargin DOF is larger, and, for the skew of the skew of exposure and the focus of projection optical system, the live width of formed optical imagery changes more hardly.

In step S106, for being selected as the common exposure nargin DOF that pays close attention to cost, the common exposure nargin in selection optimum focusing is as supplementary costs.Therefore,, in step S108, by following mode, set optimized cost.

Pay close attention to cost: the nargin of jointly exposing DOF (nm)

Supplementary costs: the common exposure nargin (%) in optimum focusing

Optimized cost: pay close attention to cost+supplementary costs

The value of the common exposure nargin in optimum focusing is larger, and the value of the nargin DOF that jointly exposes is larger.The identical direction of direction changing along the value with common exposure nargin DOF when changing conditions of exposure due to the common exposure nargin in optimum focusing changes its value, therefore, the common exposure nargin in optimum focusing is suitable for as the supplementary costs for common exposure nargin DOF.

The mask pattern shape that table 2 expression restriction is optimised in the present embodiment and 8 parameter P of efficient light sources shape _a, P _b, P _c, P _d, Ψ ₁, Ψ ₂, σ _aand σ _bvalue.In table 2, parameter P _a, P _b, P _cand P _dbe expressed as " A ", " B ", " C " and " D ".As the first embodiment, use Descended simplex method to change and be contained in the parameter value in conditions of exposure, and, change and be counted as 650.The desired value of optimized cost value is 200 or larger.

(table 2)

A	143.05	nm
			B	110.49	nm
C	403.55	nm
			D	57.03	nm

σ _a	0.873
			σ _b	0.690
Ψ ₁	70.68	Degree
			Ψ ₂	41.43	Degree

Table 13 represents the dependence that defocuses of the live width LW1 of the optical imagery that forms in the image planes of projection optical system accordingly with these conditions of exposures and LW2 and interval Gap.In Figure 13, transverse axis adopts values of defocus (mm), the longitudinal axis adopts the ratio (%) of exposure and benchmark exposure, and at this benchmark exposure place, live width LW1 and LW2 and interval Gap are ± 10% or less for the relative error (%) of their desired value.The error of the region representation live width LW1 being surrounded by 6 drawing curves shown in Figure 13 and LW2 and interval Gap is ± 10% or less exposure and the combination of focus.With reference to Figure 13, the nargin of jointly exposing DOF is 332.5nm.

Figure 14 means according to the diagram of the variation of the optimized cost value in the conditions of exposure optimization of embodiment and prior art.In Figure 14, transverse axis adopts the change counting of conditions of exposure (in comprise parameter), and the longitudinal axis adopts optimized cost value.

To describe according to the conditions of exposure optimization of the present embodiment.With reference to Figure 14, at conditions of exposure, change the stage place that counting is little, in many cases, can not obtained (that is, becoming 0) as the value of the common exposure nargin DOF of optimized cost.Therefore,, for optimized cost value, by the value of the common exposure nargin as in the optimum focusing of supplementary costs, determine to change the direction of conditions of exposure.When conditions of exposure change counting surpasses approximately 50, the value of the common nargin DOF that exposes of acquisition, and optimized cost value is by dominating as the value of paying close attention to the common exposure nargin DOF of cost.When conditions of exposure change counting surpasses 120, always obtain the value of the common nargin DOF that exposes.Be contained in the parameter value convergence (being maximized) in conditions of exposure, and conditions of exposure is determined.

On the other hand, according in the conditions of exposure optimization of prior art, even after conditions of exposure changes, the value of the nargin of jointly exposing DOF is also got 0 value continuously.Therefore, the direction of change conditions of exposure is unknown.According in the conditions of exposure optimization of prior art, solution restrains in the region not obtaining as the value of the common exposure nargin DOF of optimized cost value, and conditions of exposure can not be optimised.

< the 3rd embodiment >

As mentioned above, the invention is characterized in, as being directly set as substituting of optimized cost by paying close attention to assessment item, the function of paying close attention to cost and supplementary costs is set as to optimized cost (that is, selecting (setting) supplementary costs)).Note, can in step S106, change supplementary costs (will be selected as the assessment item of supplementary costs).In addition, can in step S122, set the optimized cost of having removed supplementary costs, that is, only as the optimized cost of paying close attention to the function of cost.

But, change supplementary costs and be not limited to the process flow diagram shown in Fig. 1 with setting optimized cost.For example, can change counting according to conditions of exposure and change supplementary costs (will be selected as the assessment item of supplementary costs).When conditions of exposure changes counting still hour, can add concern cost and supplementary costs be set optimized cost by the ratio with 1: 1.Along with conditions of exposure changes counting, increase, can set optimized cost by reducing the weight of supplementary costs.

Alternatively, as setting from the beginning substituting of supplementary costs, can when having reached certain value, conditions of exposure change counting set supplementary costs.More specifically, can when getting same value continuously as in prior art, optimized cost set supplementary costs.

The assessment item that is selected as supplementary costs is not limited to a physical quantity.An optional majority assessment item is as supplementary costs.For example, in the first embodiment, as supplementary costs, not only can select linewidth error RMS, and can select linewidth error RMS and NILS.

< the 4th embodiment >

In the 4th embodiment, the optimization (decision) of the mask pattern that description is comprised to SRAF (sub-resolution assist features (Sub-Resolution Assist Feature)) pattern.The SRAF pattern that is also referred to as auxiliary patterns is inserted into improve the performance of the image of master pattern.Therefore, SRAF pattern need to keep be not decomposed (unresolved) on substrate.

About mask pattern, in the present embodiment, as shown in figure 15, set the parameter P of the shape of distinctive (characteristic) limiting pattern (mask pattern) in smithcraft _a, P _b, P _c, P _d, P _e, P _f, P _g, P _h, P _i, P _j, and P _k.Pattern shown in Figure 15 comprise master pattern MPT1 and MPT2 and be arranged in master pattern MPT1 and master pattern MPT3 around of MPT2 and MPT4 as the master pattern that is called as In-Between.Pattern shown in Figure 15 also comprises SRAF pattern APT1, APT2, APT3, APT4, APT5, APT6, APT7, APT8, APT9 and APT10 as SRAF pattern.Parameter P _athe length that represents the limit of master pattern MPT1 and MPT2.Parameter P _brepresent the interval between master pattern MPT1 and MPT2.Parameter P _crepresent the X coordinate of mid point of master pattern MPT2 and the interval between the X coordinate of the mid point of SRAF pattern APT4.Parameter P _dthe length that represents the limit of SRAF pattern APT1.Parameter P _erepresent the interval between SRAF pattern APT1 and APT4.Parameter P _frepresent the X coordinate of mid point of master pattern MPT2 and the interval between the X coordinate of the mid point of SRAF pattern APT3.Parameter P _gthe length that represents the limit of SRAF pattern APT2.Parameter P _hrepresent the interval between SRAF pattern APT2 and APT3.Parameter P _irepresent the X coordinate of mid point of master pattern MPT2 and the interval between the X coordinate of the left part of SRAF pattern APT10.Parameter P _jand P _kthe length that represents respectively two limits of SRAF pattern APT9.

About efficient light sources, in the present embodiment, set the parameter σ of the shape that limits ring illumination _aand σ _b, as shown in figure 16.Parameter σ _arepresent outer σ value, parameter σ _bσ value in representing.

As mentioned above, in the present embodiment, set 13 parameter P that limit mask pattern shape and efficient light sources shape _a, P _b, P _c, P _d, P _e, P _f, P _g, P _h, P _i, P _j, and P _k, σ _a, and σ _b.Note, in the present embodiment, about other conditions of exposure, it is 1.35 that the NA of projection optical system (immersion liquid (immersion)) is set (fixing), exposure light wavelength is set (fixing) for 193nm, and exposure polarized state of light is set (fixing) for tangential polarization.

To the concern cost that will be set in the present embodiment be described.Figure 17 means the diagram of the example of the optical imagery forming in the image planes in projection optical system when the efficient light sources shown in Figure 16 (ring illumination) throws light on to the mask pattern shown in Figure 15.The optical imagery corresponding with master pattern MPT1, MPT2, MPT3 and MPT4 is defined as respectively MIM1, MIM2, MIM3 and MIM4.The horizontal live width of optical imagery MIM1 is defined as H1, H2, H3 and H4.(vertically) interval between optical imagery MIM1 and MIM2 is defined as V1, V2 and V3.The desired value of live width H1, H2, H3 and H4 is 70nm.The desired value of interval V1, V2 and V3 is 100nm.In the present embodiment, for the live width H1～H4 of the optical imagery of master pattern and each in the V1～V3 of interval, select with the error RMS of corresponding desired value as concern cost.Error RMS is preferably as far as possible little, thereby the optimization of optimized cost value means minimizing of optimized cost value.

To supplementary costs and the optimized cost value that will be set in the present embodiment be described.As shown in figure 17, the live width of the virtual optics image corresponding with SRAF pattern is defined as H5, H6, H7, H8, H9, H10 and H11.In addition, the live width of the virtual optics image corresponding with SRAF pattern is defined as V4, V5, V6, V7, V8, V9 and V10.SRAF pattern is auxiliary patterns as described above, and need on substrate, keep not being decomposed.Therefore, in the present embodiment, supplementary costs and optimized cost are set so that optimized cost value becomes extremely when SRAF pattern is decomposed, as will be described.Note, below, H5, H6, H7, H8, H9, H10, H11, V4, V5, V6, V7, V8, V9 and V10 will be called as SRAF and evaluate sets of line segments (evaluation line segment group).

Pay close attention to cost: the error RMS (nm) of the live width H1～H4 of the optical imagery of master pattern and interval V1～V3

Supplementary costs: 0 (when the live width of SRAF evaluation sets of line segments is 0nm)

200 (when at least one in the live width of SRAF evaluation sets of line segments is greater than 0nm)

Optimized cost: pay close attention to cost+supplementary costs

As the error RMS that pays close attention to cost, there is the value that is tens to the maximum.Therefore, supplementary costs value " 200 " ratio error RMS is much bigger.When using supplementary costs as when determining abnormal scheme as in the present embodiment, the desirable value (absolute value) of supplementary costs is preferably more than pays close attention to the desirable value of cost.

The mask pattern shape that table 3 expression restriction is optimised in the present embodiment and 13 parameter P of efficient light sources shape _a, P _b, P _c, P _d, P _e, P _f, P _g, P _h, P _i, P _j, and P _k, σ _a, and σ _bvalue.In table 3, parameter P _a, P _b, P _c, P _d, P _e, P _f, P _g, P _h, P _i, P _j, and P _kbe represented as respectively " A ", " B ", " C ", " D ", " E ", " F ", " G ", " H ", " I ", " J " and " K ".Note, in the first embodiment and the second embodiment, use Descended simplex method change conditions of exposure (in comprise parameter value).As the value of paying close attention to the error RMS of cost, be 0.38nm.

(table 3)

A

95.38

nm

F

209.29

nm

K

114.97

nm

B

71.83

nm

G

15.27

nm

σ _a

0.836

C

128.96

nm

H

224.88

nm

σ _b

0.550

D

31.24

nm

I

52.49

nm

E

65.70

nm

J

35.75

nm

Figure 18 represents the mask pattern being optimised in the present embodiment.Figure 19 represents the efficient light sources (shape) being optimised in the present embodiment.When the efficient light sources shown in Figure 19 throws light on to the mask pattern shown in Figure 18, in the image planes of projection optical system, form the optical imagery shown in Figure 17.From Figure 17, can clearly be seen that, SRAF pattern is not decomposed, and the live width of the optical imagery corresponding with each master pattern can be adjusted to desired value with high precision.

Figure 20 means the diagram of the optical imagery forming in the image planes in projection optical system accordingly with the conditions of exposure (mask pattern and efficient light sources) being optimised in prior art (that is, not considering supplementary costs).In the prior art, although as the value of paying close attention to the error RMS of cost, be 0.35nm,, as the AIM1 in Figure 20 and AIM2 indicated, SRAF pattern is decomposed.

As mentioned above, even when mask pattern that optimization (decision) comprises SRAF pattern, will not pay close attention to that assessment item is directly set as optimized cost and the function of paying close attention to cost and supplementary costs is set as to optimized cost remains effective.

< the 5th embodiment >

In the 4th embodiment, in the situation that SRAF pattern decomposes (resolution), supplementary costs is set to add exceptional value.But the setting of supplementary costs is not limited to this.For example, can set explicitly supplementary costs with master pattern rather than such as the decomposition of the specific pattern of SRAF pattern.For example, supplementary costs can be set to determine dimple (dimple) in the pattern of hole (hole) with/without, or determine the decomposition that should not occur the position of decomposing of the mask pattern that does not comprise SRAF pattern.

The mask pattern that has stood OPC (optical near-correction, Optical Proximity Correction) usually has complicated shape.Especially, the SRAF pattern that comprises insertion the mask pattern that has stood OPC have the shape of high complexity.In order to meet the recent demand for micro-composition (micropatterning), as the parameter of mask pattern, not only stipulate shape, and the factor of regulation such as phase place and transmissivity.Usually, wish to avoid the picture breakdown of the position beyond the position of master pattern.But, when mask pattern becomes complexity, the position of the risk that is more difficult to grasp picture breakdown of becoming.In this case, can effectively set supplementary costs to prevent the picture breakdown of the position beyond the position of master pattern.

Can for example with suitable pitch, set for determining whether to have occurred the position of picture breakdown in the region of predetermined distance with master pattern.Can in the whole region beyond the position of master pattern, set and will be used to determine the evaluation line segment that whether has occurred picture breakdown.The former is favourable reducing in required time of optimization and data volume.The latter is more favourable in the risk of determining more accurately picture breakdown.

< the 6th embodiment >

In the 4th and the 5th embodiment, described when add the situation of exceptional value with supplementary costs in the time should not occurring that decomposition (having obtained the live width of optical imagery) has appearred in the position of decomposing.But, the invention is not restricted to this.For example, can be less than and when particular value or MEEF are greater than particular value, add exceptional value at NILS.Note, MEEF is the abbreviation of mask error enhancer (Mask Error Enhancement Factor), and the size of the scale error occurring in projecting to the pattern on wafer while representing to have occurred to have the scale error of particular value in the pattern on mask when mask is manufactured.

In the 3rd embodiment, consider that the value of assessment item (physical quantity) self is as supplementary costs.But, can consider that abnormal definite condition of value of assessment item is as supplementary costs.More specifically, supplementary costs can be set as follows.

Supplementary costs: 0 (value of paying close attention to the NILS of pattern is 1.4 or larger)

50 (value of paying close attention to the NILS of pattern is less than 1.4)

Supplementary costs: 0 (value of paying close attention to the MEEF of pattern is less than 5)

100 (value of paying close attention to the MEEF of pattern is 5 or larger)

Note, for setting the assessment item of the supplementary costs that is used as abnormal definite condition, be not limited to specific assessment item.

Other embodiment > of <

Also can by read and the program of executive logging on memory device with carry out the system of function of the above embodiments or the computing machine of device (or such as CPU or MPU equipment) and by the computing machine by system or device by for example reading and the program of executive logging on memory device carried out the method for its each step to carry out the function of the above embodiments, realize each aspect of the present invention.For this purpose, for example via network or for example, from the various types of recording mediums (, computer-readable medium) as memory device, to computing machine, provide program.

Although described the present invention with reference to exemplary embodiment, should be understood that and the invention is not restricted to disclosed exemplary embodiment.The scope of following claim should be endowed the 26S Proteasome Structure and Function of the widest explanation to comprise all such alter modes and to be equal to.

Claims

1. a determining method that determines the conditions of exposure in exposure device, described exposure device comprise for the illumination optical system of mask illumination is unified for by the image projection of the pattern of mask to the projection optical system on substrate, described method comprises the following steps of being carried out by processor:

First step, from a plurality of assessment items, select to pay close attention to assessment item, described a plurality of assessment item is image calculation from forming in the image planes of projection optical system accordingly with conditions of exposure, for by comparing and evaluate described image with the target pattern that will form on substrate;

Second step, from described a plurality of assessment items, select with pay close attention to assessment item different and when the parameter value of conditions of exposure changes along the auxiliary evaluation project of the identical direction change value of the directions of value change with paying close attention to assessment item;

Third step, sets and comprises the evaluation function of paying close attention to assessment item and auxiliary evaluation project;

The 4th step, change the parameter value of conditions of exposure so that the value of described evaluation function more approaches desired value, and each in a plurality of images that form in the image planes of projection optical system accordingly for the parameter value after the change with conditions of exposure, calculates the value of described evaluation function; And

The 5th step, determines among a plurality of values of the described evaluation function calculate in the 4th step the parameter value of the conditions of exposure corresponding with the value of evaluation function that meets desired value.

2. according to the process of claim 1 wherein, in second step, for parameter value, the value of selected auxiliary evaluation project is less than the value of paying close attention to assessment item.

3. according to the process of claim 1 wherein, in second step, selected auxiliary evaluation project is paid close attention to the height of assessment item for the remolding sensitivity of the variation of parameter value.

4. according to the process of claim 1 wherein, in second step, the value of selected auxiliary evaluation project changes continuously when parameter value is changed.

5. according to the process of claim 1 wherein, in second step, by reference, represent the table of the corresponding relation between described a plurality of assessment item, select auxiliary evaluation project.

6. according to the method for claim 1, wherein, if a plurality of values of the evaluation function calculating in the 4th step are discontented foot-eye value all, select so the assessment item different from the auxiliary evaluation project of selecting in second step as new auxiliary evaluation project, and, carry out third step, the 4th step and the 5th step.

7. according to the process of claim 1 wherein, if at least one in a plurality of values of the evaluation function calculating in the 4th step meets desired value, so, described method also comprises:

The 6th step, sets and only has the new evaluation function of paying close attention to assessment item;

The 7th step, in the number of times that the parameter value of conditions of exposure is limited from the parameter value change determining the 5th step, for each in a plurality of images that form in the image planes of projection optical system accordingly with parameter value, the value of the new evaluation function that calculating is set in the 6th step, to make the value of the new evaluation function set in the 6th step more approach desired value; And

The 8th step, from a plurality of values of the evaluation function that calculates the 7th step, determines the parameter value of the conditions of exposure corresponding with the value of evaluation function that meets desired value.

8. according to the process of claim 1 wherein, in third step, set evaluation function, the value that makes to pay close attention to assessment item more approaches the direction that the direction of desired value and the value of auxiliary evaluation project more approach desired value and mates.

9. basis the process of claim 1 wherein,

The depth of focus in the image planes that described concern assessment item is projection optical system, and,

Described auxiliary evaluation project comprises with lower at least one: the difference between the size of the image of the pattern of the size of target pattern and the mask that forms in the image planes of projection optical system; Exposure nargin with the image of the pattern of the mask forming in the image planes of projection optical system.

10. according to the process of claim 1 wherein, conditions of exposure comprises with lower at least one: the shape of the pattern of mask; With the light intensity distributions that will form on the pupil plane of described lamp optical system.

11. 1 kinds of execution are according to the computing machine of the determining method of claim 1.

12. 1 kinds of determining methods that determine the conditions of exposure in exposure device, described exposure device comprise for the illumination optical system of mask illumination is unified for by the image projection of the pattern of mask to the projection optical system on substrate, described method comprises the following steps of being carried out by processor:

In the parameter value that changes conditions of exposure, calculate the value of the assessment item of the image forming in the image planes of using in projection optical system, be used for by comparing and evaluate this image with the target pattern that will form on substrate, and determine the step of the parameter value of the conditions of exposure corresponding with the value of assessment item that meets desired value

Wherein, assessment item comprises assessment item and the auxiliary evaluation project paid close attention to, described auxiliary evaluation project different with concern assessment item and in the immovable situation of the value of paying close attention to assessment item when parameter value is changed change value.

13. 1 kinds of determining methods that determine the conditions of exposure in exposure device, described exposure device comprise for the illumination optical system of mask illumination is unified for by the image projection of the pattern of mask to the projection optical system on substrate, described method comprises the following steps of being carried out by processor:

Wherein, assessment item comprises assessment item and the auxiliary evaluation project paid close attention to, and described auxiliary evaluation project is got exceptional value during with concern assessment item image abnormity different and that form in the image planes in projection optical system.

14. 1 kinds of execution are according to the computing machine of the determining method of claim 12.

15. 1 kinds of execution are according to the computing machine of the determining method of claim 13.